In particular, the pump is intended to be provided on a bottle wherein the product is conditioned, in particular a liquid product, a gel, a lotion or a cream, for example a care, makeup or perfumery cosmetic product, or a pharmaceutical product. In this application, the pump can be actuated manually in order to take the product and pressurise it with a view to dispensing it, for example in the form of an aerosol, a stream or a dab of product.
The pump comprises a body having a casing wherein a nozzle is mounted in reversible translation by defining inside said casing a metering chamber with variable volume. In order to allow for the supplying of the metering chamber with product, the casing is provided with an inlet orifice in communication with the conditioned product, with the metering chamber having an outlet valve for the pressurised product in said chamber.
The inlet orifice is provided with a valve comprising a ball which is retained in a cage in order to be displaced between a closed position and an open position of said orifice. In particular, on a dispensing stroke of the nozzle, the pressure in the metering chamber thrusts the ball in a sealed manner on the inlet orifice and, on a suction stroke of said nozzle, the vacuum in the metering chamber lifts the ball into open position of the inlet orifice in order to allow for the supplying of said chamber with product.
In order to carry out such a pump body, document EP-1 578 537 provides for:                moulding the casing by forming, on the inside of a peripheral wall surmounting the inlet orifice, ribs in relief which extend axially by being spaced angularly, with each of said ribs having two lateral faces that join together along an internal edge in order to delimit the cage between said edges, as well as an upper end having a free upper surface;        introducing the ball into the cage below the upper ends;        plastically deforming the upper ends in order to form visors extending radially towards the interior of the casing, said visors being arranged to imprison the ball in the cage.        
In particular, the casing can be carried out by pressurised injection of a thermoplastic material of the polyolefin type, with the ductility of the ribs then authorising the cold heading of their free upper surface. As such, it is possible to combine a facility of moulding axial ribs with a reliability of the radial closing of the cage in order to imprison the ball. This is achieved without requiring an added part.
EP-1 578 537 proposes that the upper free surfaces of the ribs have a plane geometry forming an acute angle with the peripheral wall in order to facilitate the radial pulling back of the upper ends during the plastic deformation.
However, a fortiori at industrial production speeds of a magnitude of 5 to 10 parts per second, this production causes a sudden creeping of the material during the heading, weakening the bead of creep material which is then able to break into fragments which can mix with the product distributed.
Moreover, the geometry of the ribs according to prior art complicates the carrying out of the mould for producing the casing, in particular by requiring the use of a method of electro-erosion using pointed electrodes, which are fragile, in order to carry out as a hollow the moulding cavities of said ribs.